Shouldn't the lens stabilizer motor humming noise go silent after I flip stabilizer switch to OFF?

[blouse]

Camera: EOS R8
Lens: RF24–105mm F4-7.1 IS STM

When the camera is on, if I put my ear to the lens, I can hear the stabilizer motor humming. If I flip the stabilizer switch to OFF, I expect to hear it go silent, but it's still humming. Why?

(the stabilizer effect does turn off, tested by shooting videos)

(my old EF lens does go silent immediately after flipping the switch, tested on the same camera body, using the RF mount adapter ring)

[deebatman316]

Are you sure you're not hearing the lens' AF motor.

[blouse]

Yes I'm sure, it's a constant humming noise, without any button press, never stops unless the camera is powered off.

If you're unfamiliar with the noise, the easiest way to hear is: turn off your camera -> put your ear onto the lens body -> turn on the camera. (if you try that, I'd greatly appreciate if you could tell me what you hear after flipping off the stabilizer switch)

[deebatman316]

On mirrorless cameras the AF motor is always on even when not active pressing the shutter button. This is because the camera is always tracking.

[blouse]

No, what you described is Preview AF, under the AF menu. It's disabled by default, and you should probably turn off yours, unless you have a specific reason to need it. It's a constant battery drain because when you're walking, the camera keeps focusing on random things (typically the ground), when you're not even using the camera.

[deebatman316]

I don't have a mirrorless camera I have a 5D Mark IV. I tested on a friend's camera with that turned off.

[blouse]

Hi Demetrius, I'm sorry but you didn't mention what did you test, and what did you hear?

[p4pictures]

Check to see if you have Preview AF enabled? You will find this setting in the AF menu section. From memory it’s on page 3 or 4. 

[blouse]

No, Preview AF can only be heard when the camera is trying to acquire focus, but the stabilizer is a constant hum. My Preview AF is turned off too.

When you turn your camera from off to on, I'm sure you can hear the stabilizer spinning up, as long as you put your ear on the lens body and listen.

[Waddizzle]

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@blouse wrote:

No, Preview AF can only be heard when the camera is trying to acquire focus, but the stabilizer is a constant hum. My Preview AF is turned off too.

When you turn your camera from off to on, I'm sure you can hear the stabilizer spinning up, as long as you put your ear on the lens body and listen.

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Try resetting the camera back to factory defaults, and then disable “Preview AF”